BACKGROUND Lichen amyloidosis (LA) is a chronic, severely pruritic skin disease, which is the most common form of primary cutaneous amyloidosis. The treatment of LA has been considered to be difficult. LA may be associated with atopic dermatitis (AD), and in this setting, the treatment options may be more limited. Herein, we report four cases of LA associated with AD successfully treated by dupilumab. CASE SUMMARY In this article, we describe four cases of patients who presented with recurrent skin rash accompanied by severe generalized intractable pruritus, diagnosed with refractory LA coexisting with chronic AD. Previous treatments had not produced any apparent improvement. Thus, we administered dupilumab injection subcutaneously at a dose of 600 mg for the first time and 300 mg every 2 wk thereafter. Their lesions all markedly improved. CONCLUSION Dupilumab may be a new useful treatment for LA coexisting with AD.